1. Field of the Invention
This invention relates to a modified basil essential oil and a process for the production thereof. More particularly, it relates to a basil essential oil which has been improved in its odor or aroma so as to be effectively available as a perfume material for use in, for example, compound perfumes to elevate the content of specific components thereof. The present invention also relates for treating basil essential oil in such a manner as to elevate the content of specific components.
2. Description of the Prior Art
Natural basil essential oil widely used for compound perfumes in various cosmetics, perfumes and the like, contains estragole and linalool as the major components. It is thought that basil essential oil further contains a number of sesquiterpene hydrocarbons and oxygenated sesquiterpenes in trace amounts.
However it is very difficult to synthesize the aforesaid sesquiterpene compounds. It is known that the content of sesquiterpene compounds in basil essential oil can be elevated by steam distillation. However the distillate thus obtained usually comprises 10% by weight of sesquiterpene hydrocarbons, 0.3% by weight of oxygenated sesquiterpenes, 60 to 80% by weight of estragole, 10 to 40% by weight of linalool and 5% by weight of eugenol. Estragole exists as the major component, and substances of similar properties are contained together therein. This makes it very difficult to separate the sesquiterpene compounds at a high yield. Thus a method of efficiently separating these components on an industrial scale has not been developed.
In order to produce a compound perfume having the smell of sesquiterpene compounds accentuated, it is therefore necessary to use a large amount of basil essential oil. As a result, the content of estragole and linalool as the major components is undesirably increased, which makes it difficult to obtain a compound perfume having a desired note. Thus the range of application of basil essential oil as a perfume material is restricted.